There are 2 ways that you can choose to increase the maximum upload file size in WordPress.

1. Update .htaccess file

php_value upload_max_filesize 128M 
php_value post_max_size 128M 
php_value memory_limit 256M 
php_value max_execution_time 300 
php_value max_input_time 300

Change the numbers to the values that you need. The max execution time and max input time values are in seconds and might need to be increased further if your internet connection is slow.

2. Update wp-config.php file

@ini_set( 'upload_max_filesize' , '128M' ); 
@ini_set( 'post_max_size', '128M'); 
@ini_set( 'memory_limit', '256M' ); 
@ini_set( 'max_execution_time', '300' ); 
@ini_set( 'max_input_time', '300' );